Internal-combustion engine



Sept. 25, 1923.

J. DAVIDSON INTERNAL COMBUST I ON ENGINE Filed June 29 1920 ffirz W EHaM Patented Sept. 25, 1923.

JOHN DAVIDSON, OF BURTON-oli TRENT, ENGLAND.

INTERNAL-COMBUSTION ENGINE.

Application filed June 29,} 1920. Serial No. 892,754.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L.,-1313.)

To all whom it may concern:

Be it known that I, JOHN DAVIDSON, a British subject, residing at Burton-on-Trent, 1n the county of Stafford, England, have invented certain useful Improvements in Internal-Combustion Engines, for which I have made application for patent in Great Britain, No. 119,414, dated April 16th, 1918; in Belgium, No. 279,692, dated April 5th,

1919; and France, No. 497,801, dated April 3rd, 1919, and of which the following is a specification.

This invention relates to internal combustion engines and the object of this invention is to render the same generally more eflicient in action, than hitherto has been the case.

In an internal combustion engine constructed in accordance with this invention, a slide valve driven, from the crank shaft is employed between twopairs of cylinders for the distribution of the working fluid to each pair of charging pumps and respective working cylinders.

A further important feature of my invention consists in connecting working pistons of the engine to the pump piston or pistons in spaced relation thereto whereby the undersides of the working pistons are cooled, and for high power engines, in providing three or more working pistons for each charging pump. Furthermore according to my invention a jacket or jackets are provided on the charging pump barrel or barrels and are connected to the exhaust outlet or outlets of the engine, the arrangement being such that a part or the whole of the exhaust gases from theengine circulate through said jacket or jackets and heat the charging pump or pumps, whereby condensation of the gas or mixture in the pump or pumps is prevented and the efliciency' of the engine is increased.

I attain my 0 ject by the mechanism illustrated in the accompanying sheet of drawings, in which Figure 1 is a view in vertical section of an internal combustion engine having a s" 1e pumping action.

igure 2 is a detached vertical section of a modified form of wor piston.

Figure 3 is a detached sectional plan view on line A-A of Flgure 1.

Similar numerals- IBfQl: to similar parts throughout the several views.

Referring to Figures 1 and 3 of the drawl ings, 1, 2 and 3, 4 are the working cylinders and in the former are formed the inlet ports 5, 6.

Similar ports 7 8 are also formed in the cylinders 3, 4 to act as exhaust ports. The working pistons 9, 10 and 11, 12 aremounted on and fixed to the large diameter or charging piston 13, 14 which reciprocate in the. cylinders 15, 16 formed below the working cylinders. the walls of cylinders 15, 16, the upper side of. pistons 13, 14 and the under sides of the working istons 9, 11, 10, 12 form the charging cylin ers. P

The piston valve 17 which is driven from the crankshaft 18 by means of an eccentric 19, controls the admission and discharge of the mixture to and fromthe charging cylinders 15, 16. j

The piston valve 17 is also arranged in communication with the port 20 and the aseous fuel and air are admitted to the inside of the piston valve 17. By means 0 the ports 21, 22, communica- The' pa e enclosed betwe tion is established between the charging cylinders 15, 16 and the valve 17 fuel being admitted through slots 23 formed in the valve 17. A Y pipe 24 connects together the passage 26 around the piston valve 17 and 25 and the inlet cylinder ports 5, 6.

The above described engine operates as follows 4 The charging piston 13 of the left hand engine is shown at the top ofits stroke. As it moves downwards, the piston valve 17 moves upwards and by means of the bottom slots 23 and the inner part thereof puts the port 21 ofthecharging'cylinder 15 in connection with the mixture inlet 20 and allows a charge of gaseous fuel and air to be the exhaust ports 8 and allows the exhaust gases in the cylinders 2, 4',--to escape. Immethe exhaust ports 8 and the inlet ports 6 are covered by the pistons 10 and 12 after which the charge is compressed above the pistons 10, 12 in the cylinders 2, 4 and fired in the usual manner.

From the above description it will be seen that the charging cylinder 15 charges the working cylinders 2, 4. i

In a precisely similar manner the charging cylinder 16 charges theworking cylinders 1 3.

One or more sets of piston rings 27 are fitted to the bottom of the working pistons 9,11, 10, 12 in addition to the rings 28 at the to thereof the arrangementbeing such that t e pump cylinders 13 and 14 at all points of the stroke, are effectively sealed from the exhaust ports 7 and 8. The working pistons 9, 11, 10, 12 are of short length and therefore of low weight and a reduction of frictional resistance is thus obtained.

Moreover the working pistons 9, 11, 10 12 are I the purpose of enabling the charge of gas,-

formed with hollow annular spaces 29 which are open at the lower ends.

Each of the working pistons 9, 11, 10, 12 is held in spaced relation to the corresponding charging piston 13, 14 by a rod 30 which in the example illustrated is formed hollow and cast on the working piston 9, 11', 10, 12 being secured to the charging piston 13, 14 by a flange 31 and bolts 32, see Figure 3. The bolts32 also serve to hold brackets 33 in which the connecting pin 34 is fixed. The lower ends of the working pistons 9, 11, .10, 12 are thus open to the pump cylinder for air or combustible mixture drawn in by the charging piston to have a cooling action on the working pistons, and thus permitting a hi her load to be carried by the engine.

igure 2 illustrates a modified construction of working piston in which the working piston is divided into two parts 35 and 36, the part 36 being cast on the hollow rod 30 and carrying the piston rings 27 which serve to seal the exhaust ports of the engine from the charging cylinders 13 and 14. A

- hole or holes 37 may be provided in the rod 30 to allow the chargeof gas or the' like to enter the same and increase the cooling effect on the upper 7 art 35 of the working piston The herein efore described and hereinafter claimed im rovements are applicable to all engines having a plurality of working istons connected to a charging piston inuding those constructed to pperate on the admi-Diesei principle.

messes In order to prevent condensation of the combustible mixture in the pump cylinders 15 and 16, Figure 1, I surround the charging pump cylinders 15 and 16 with a jacket 48 which in depth may be equal to the length of the whole or only a part of the stroke of the charging pump pistons 13,14. At one side or end of the engine the jacket 48 is provided with an inlet 49 and at the other side or end I provide an outlet 50. The inlet 49 and outlet 50 are preferably situated as illustrated in different planes in addition to being arranged atopposite sides or ends of the engine and a partition or partitions may "50 and inlets 49 may be provided for the purpose of uniformly I distributing the heating action of the exhaust gas over the whole or a part of the charging pump cylinder or cylinders 15 and 16. Furthermore the arrangement may be such for example as illustrated that only a portion of the exhaust gases from the engine circulate through the acket or jackets 48.

The use of a jacket or jackets as hereinbefore described is particularly useful when parafiin is employed for fuel, or the engine is running on light loads, and consuming paraflin orany' other fuel.

' I claim: 1 p p 1. In an internal combustion engine, in combination a crank shaft, a pair of charging pistons connected to the crankshaft with angular displacement of-substantially 180 degrees; a plurality of working pistons rigidly connected to each charging piston; an eccentric on the crank shaft, a hollow piston valve operatively connected to said eccentric and situated between the charging pistons; charging cylinders containing the charging pistons, working cylinders containing the working pistons and forming open extensions of the charging cylinders; a valve casing containing the hollow piston valve open-at one end; ports leading from the charging cylinders to the valve casing and opening into the valve casing at opposite piston valve at each side of the middle thereof and cooperating with the ports leading from the charging cylinders; and an annular constriction at the middle of the hollow piston valve; co-operating with the common opening of the inlet ports to the working cylinderfor the hereinbefore specified purpose. i Y

2. In an internal combustion engine, a plurality of hollow working pistons; a work ing chamber containing said pistons; a charging piston rigidly fixed to said Working pistons; a charging chamber forming an extension f said working chamber and containing said charging piston; a sliding piston valve controlling the passage of combustible mediumv from the vcharging piston to the working pistons; an open end and a closed end on each of said hollow pistons; hollow connecting members of less-diameter than said working pistons rigidly connected to the closed ends of the working pistons and to the charging piston; and openings in the hollow connecting members allowing medium having a cooling efiect to enter the interior of the hollow working pistons.

3. In an internal combustion engine, a plurality of working pistons, an annular depending skirt with open bottom on each of the Working pistons, a chamber containing said pistons; a charging chamber forming a COIltlIl'llOllSBXtBl'lSlOIl of the working chamher communicating therewith; a charging piston in the charging chamber; rod members wholly Within the working and chargworking piston and with the charging piston and retaining the working piston a fixed distance awayv from the charging piston.

Signed at Manchester, in the county of Lancaster, England, this 14th day of June, 1920.

JOHN DAVIDSON.

Witnesses: MARY I. BOSSHARDT, ALFRED BossHARp'r. 

